Disc player having a transporting device for moving a disc and disc holder

ABSTRACT

A disc player has a playback unit that includes a turntable having a driveshaft. At least one disc storage magazine having a plurality of storage compartments and a plurality of superposed disc holders stored therein is provided. Each disc holder accommodates one disc. Also provided is a transporting device movable in a direction towards the disc storage magazine for moving a desired disc and respective disc holder back and forth between the storage compartment and the playback unit. The transporting device includes a horizontally displaceable extraction device for extracting the respective disc holder. The transporting device also has a disc hold-down member for pressing the desired disc to be played onto the turntable. Further, the transporting device includes a movable carrying arm for accommodating the respective disc holder. The movable carrying arm has an upper face including a cover for gripping over the respective disc holder and disc therein. The cover has an opening essentially coaxial with a longitudinal axis of the drive shaft. The disc hold-down member is insertable into the opening.

BACKGROUND OF THE INVENTION

The invention relates to a disc player having at least one disc storagemagazine in which a plurality of superposed disc holders each holdingone disc are stored in storage compartments, the disc player furtherincluding a transporting device which is movable in the stackingdirection of the disc storage magazine to move a desired disc back andforth together with the associated disc holder between the storagecompartment and a playback unit. The transporting device is providedwith a disc holder extraction device which is horizontally displaceableon the transporting device, a disc hold-down member for holding the discto be played against the turntable of the playback unit and a carryingarm for accommodating a disc holder.

Such a disc player is known from DE 3,922,721.A1. Here the carrying armof the transporting device is configured in the shape of a U in order toaccommodate a disc holder with a disc deposited therein. The extractiondevice of the transporting device transports the disc holder holding theselected disc on appropriately arranged carrying rails on the upper faceof the carrying arm. In the final position of the disc holder on thecarrying arm, in which the disc is concentric with the turntable of theplayback unit, the disc holder as well as the disc are not protected, onthe one hand, against soiling and, on the other hand, against improperaccess. If no disc is being played, the carrying arm of the transportingdevice stands empty in its starting position above the playback unit. Inthat case, because of the U-shaped and thus open configuration of thecarrying arm, the playback unit and particularly its playback head aresubjected to soiling and to the danger of improper treatment.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a disc player of theabove-mentioned type which, with a simple and compact structure, ensuresa reliable shield for the disc holder and the desired disc againstextraneous influences during transport to and from the playback unit andfor the playback unit itself.

This is accomplished by the invention in that the upper face of themovable carrying arm is provided with a covering that completely coversthe disc holder and the disc therein.

The measure according to the invention always protects the disc and thedisc holder against soiling by dust and the like on its transportingpath. At the same time, the covering prevents access to the disc or thedisc holder, thus preventing possible damage to the transporting unit.If no disc is being played, the transporting device and the carrying armare in their starting position directly above the playback unit. In thisposition the covering of the carrying arm shields the playback unitcompletely against soiling and improper access, which is of particularsignificance for the playback head of the playback unit.

To be able to detect, on the one hand, the imprinted identifying data ofthe selected disc during its transport and, on the other hand, observeits rotary movement during playing of the disc, an advantageous featureof the invention provides for the covering of the carrying arm to beconfigured as a transparent pane in the region of the disc.

According to an advantageous modification of the subject matter of theinvention, the underside of the carrying arm is provided with twoparallel holding rails for the disc holder. These rails are spaced at adistance that is slightly less than the width of the disc holder. Inthis way, the underside of the carrying arm together with the discholder it carries and the disc disposed therein practically form a planesurface which makes it possible to employ playback units from differentmanufacturers and thus of different exterior design in the disc player.Since there are no projections or the like at the underside of thecarrying arm, they cannot interfere with the downward movement of thecarrying arm by bumping against the housing of the playback unit whenthe disc is placed onto the turntable of the playback unit.

To avoid the empty movement of the transporting device toward theplayback unit after the selection of a disc, a further advantageousfeature of the invention provides the carrying arm with an associatedsensor for monitoring the actual presence of a disc in the disc holder.Preferably, a sensing device for determining the size of the diameter ofthe disc in the disc holder is associated with the carrying arm.

For monitoring the correct position of the disc holder on the holdingrails of the carrying arm of the transporting device, an advantageousmodification of the invention associates the middle of the carrying armwith a sensor for monitoring the concentric position of the disc storedin the disc holder relative to the turntable of the playback unit.

Advisably, a sensor for determining the end position of the carrying armabove the playback unit is disposed in the lower portion of thetransporting device.

In order to realize a structurally simple arrangement of the dischold-down member, the cover associated with the carrying arm is providedwith an opening that lies in the longitudinal axis of the drive shaft ofthe turntable of the playback unit into which the disc hold-down memberis inserted. Preferably, the disc hold-down member includes a dischold-down insert equipped with a central magnet and disposed withrelatively large play in the opening in the cover. In the rest positionof the disc hold-down insert, the magnet cooperates with a magnetizablesteel plate that is inserted into the cover closing the opening, and inthe operating position of the disc hold-down insert the magnetcooperates with the magnetizable drive shaft of the turntable of theplayback unit. As an alternative, it is also possible to manufacture thecover itself of magnetizable steel.

In order to realize a simply constructed and reliably operatingextraction device for the transporting device, in which a gripping armmounted so as to be moved in and out in a reciprocating carriage in theextraction device can be brought into engagement with an associatedrecess in the disc holder and in which the gripping arm is retained inits extended position by a stationary abutment, an advantageousmodification of the invention provides that the gripping arm, if thecarriage is in its starting position, is held in its moved-in positionby a cam track guide in such a way that, if the carriage moves from itsstarting position, the cam track guide moves the gripping arm into themoved-out position in which it engages in the recess in the disc holder.Advisably, the cam track guide includes a cam track block that isconnected with the gripping arm and a pin that enters into a cam trackin the cam track block and is fastened to the upper portion of thetransporting device. The cam track in the cam track block is herepreferably configured in such a way that, if the carriage moves into itsstarting position defined by an abutment, the pin initially comes intoengagement with the cam track and then, by way of the cam track block,pulls the gripping arm back into its moved-in position in the carriage.

In order to realize a simple guidance for the cam track block and thegripping arm, an advantageous feature of the invention provides that thecarriage, which is slidably guided on a supporting rod, is provided onits upper face with two facing flanges that are equipped with openingsin which, on the one hand, the cam track block and, on the other hand,the gripping arm are slidably guided. Advisably, the interior of theflange accommodating the gripping arm of the carriage serves as theabutment for the cam track block when the gripping arm is in theextended position.

In order for the carriage to be unable to pivot about the supportingrod, the carriage of a modification of the invention is supported in theregion of the gripping arm on a rail that extends parallel to thesupporting rod. Preferably, the cam track block of the gripping arm hasan associated light barrier for detecting the starting position of thecarriage.

For reliable back and forth movement of the carriage, an advantageousmodification of the invention provides that the carriage is driven byway of a belt drive and worm gear and by a reversible motor, with afriction coupling being provided between the worm gear and the drivewheel of the toothed belt of the belt drive. The friction couplingpermits manual displacement of the carriage.

In order to be able to employ two analogously configured extractiondevices for processing two oppositely disposed disc storage magazineswith the same transporting device, a further carriage is advisablyprovided on the supporting rod for two oppositely disposed disc storagemagazines. This carriage is driven by way of a further belt drive withworm gear, friction coupling and reversible motor so as to slidablymove. In order to actuate the gripping arm of this carriage, the latteris also connected with a cam track block and a correspondingly extendingcam track which has a further pin associated with it that is arrangedcorrespondingly at the upper portion of the transporting device.

BRIEF DESCRIPTION OF THE DRAWINGS

The concept on which the invention is based will now be explained ingreater detail in the description below of an embodiment that isillustrated in the drawings in which:

FIG. 1 is a perspective front view of a disc player according to theinvention;

FIG. 2 is a top view to an enlarged scale of the transporting device ofthe disc player of FIG. 1 with the drive for the up and down movementbeing omitted;

FIG. 3 is a side view, partially in section, of the transporting deviceaccording to FIG. 2;

FIG. 4 is a detail view to an enlarged scale of the disc hold-downmember of the transporting device of FIG. 3 in an alternative embodimentwith associated playback unit;

FIG. 5 is a partial bottom view of the disc hold-down member of FIG. 4;

FIG. 6 is a view of the disc hold-down member of FIG. 4 in the operatingposition;

FIG. 7 is a partially sectional view of the transporting device of FIG.2;

FIG. 8 is a view of the transporting device of FIG. 7 with associateddisc holders on its sides in the operational position;

FIG. 9 is a partially sectional rear view of the transporting device ofFIG. 8;

FIG. 10 is a cross-sectional view of the bottom portion of thetransporting device of FIG. 9; and

FIG. 11 is a front view of the illustration of FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The disc player 1 with which informations recorded on discs can be readout and played back optically includes a housing 2 with an associatednon-illustrated operating panel provided with various keys, for example,a disc selection key, a disc playback key and a stop key. Exchangeabledisc storage magazines 3 are arranged in the sides of housing 2 so as toface one another. In the space between disc storage magazines 3 there isdisposed a transporting device 4 that can be moved up and down. Itaccommodates a disc holder 6 which receives a disc 5. A playback unit 7including a driven turntable 8 and a pivotal playback head 9 areattached in a stationary manner between and below the two facing discstorage magazines 3. The mutually identically constructed disc storagemagazines 3 are each provided with a plurality of superposed storagecompartments 10 for storing a corresponding number of disc holders 6,each accommodating one disc 5. In storage compartment 10, the positionof disc holder 6 is secured by two facing non-illustrated springelements which are attached to disc storage magazine 3. In thisposition, disc holder 6 projects to such an extent over the extractionside of disc storage magazine 3 that it can be gripped by an extractiondevice 11 that is part of transporting device 4.

Disc holder 6 is provided with a recess 13 in the front region of theunderside of each of its long sides 12. According to the association oftransporting device 4 with disc storage magazine 3 and the insertionposition of disc holder 6 in storage compartment 10, a gripping arm 14of extraction device 11 of transporting device 4 is able to engage inone of these recesses 13 in order to transport disc holder 6 to arectangular carrying arm 15 at the upper portion 16 of transportingdevice 4. Carrying arm 15 has two associated holding rails 17 at itsunderside. These holding rails extend in the direction of the long sides12 of disc holder 6 so as to accommodate the disc holder 6. The distancebetween the mutually parallel holding rails 17 is somewhat less than thedistance between the long sides 12 of disc holder 6 so that disc holder6 can be received by holding rails 17 and moved in a sliding manner. Theholding rail 17 at the free end of carrying arm 15 is fastened directlyto the latter while the other holding rail 17 is attached to the lowerportion 18 of transporting device 4. Due to this type of support fordisc holder 6 in carrying arm 15, disc holder 6 forms a planar surfacewith the underside of carrying arm 15, thus making it possible to inserta playback unit 7 having any desired exterior configuration into housing2 since no projections or the like at the underside of carrying arm 15interfere, by abutting on playback unit 7, with the necessary downwardmovement of the transporting device when a disc 5 is placed ontoturntable 8. The upper face of carrying arm 15 is configured as a closedcover 19 for the disc holder 6 disposed therebelow and its associateddisc 5. At the same time, if transporting device 4 is in its startingposition shortly above playback unit 7, cover 19 serves as dustprotection for playback unit 7. In the region of the disc 5 held by discholder 6, cover 19 is constructed as a transparent pane 20 to permitobservation of disc 5. Pane 20 is provided with a sensor 21 for actuallychecking for the presence of a disc 5 in the plate holder 6 picked up bythe carrying arm 15 of transporting device 4. If sensor 21 does notdetect a disc in disc holder 6, transporting device 4 immediatelyreturns this disc holder 6 to the associated storage compartment 10 ofdisc storage magazine 3.

A disc hold-down member 22 is inserted concentrically into pane 20 ofcarrying arm 15 of transporting device 4. A disc hold-down insert 25 ofdisc hold-down member 22 extends with a relatively large play through anopening 24 in pane 20 that lies in the longitudinal axis of the driveshaft of turntable 8 of playback unit 4. Disc hold-down insert 25 holdsa magnet 26 in its center which faces a magnetizable steel plate that isclipped into the underside of a plastic lid 27 covering opening 24. Dueto the action between magnet 26 and steel plate 28, disc hold-downinsert 25, in its rest position, lies against steel plate 28. Iftransporting device 4 and disc hold-down member 22 move into their endposition above turntable 8, the magnetic shunt between magnet 26 and themagnetizable drive shaft 23 of turntable 8 becomes greater than themagnetic shunt between magnet 26 and the magnetizable steel plate 28,thus displacing disc hold-down insert 25 downwardly out of opening 24 sothat three knobs 29 that are disposed on its underside in an arrangementmutually offset by 120° push disc 5 onto turntable 8. As soon as dischold-down member 22 is moved out of this operating position again, themagnetic flux between magnet 26 and steel plate 28 causes disc hold-downinsert 25 to go back to its rest position. An annular shoulder 30 ofdisc hold-down insert 25 prevents disc hold-down insert 25 from beingpulled out of opening 24 in pane 20 of carrying arm 15. Instead of steelplate 28, lid 27 may also be made of a magnetizable material.

The gripping arm 14 of extraction device 11 of transporting device 4 ismounted so as to move in and out in a carriage 31. By means of a beltdrive 34 carriage 31 is thus able to move back and forth in the lowerportion 18 on a supporting rod 33 equipped with abutments 32. In thestarting position, carriage 31 lies against abutment 32 and gripping arm14 is held in its moved-in position in carriage 31 by way of anassociated cam track guide 35. Cam track guide 35 is composed of a camtrack block 36 which is connected with gripping arm 14 and is providedwith a cam track 37 into which engages a pin 38 that is fastened toupper portion 16. On its upper face, carriage 31 is provided with afrontal flange 39 equipped with an opening 40 through which extendsgripping arm 14 in a manner enabling it to slide. The carriage furtherincludes a rear flange 41 provided with an opening 42 through whichextends cam track block 36 in a manner enabling it to slide. Theinterior face of front flange 39 serves as an abutment for cam trackblock 36 when gripping arm 14 is in the extended position. In the regionof gripping arm 14, the underside of carriage 31 is supported on a rail43 that is attached to lower portion 18 parallel to support rod 33. Inthe starting position of carriage 31, the portion of cam track block 36that projects beyond the rear flange 41 of carriage 31 engages in alight barrier 44 that is configured as a fork coupler to thus monitorthis position of carriage 31. Light barrier 44 is attached to a printedcircuit board 45 which is fastened to lower portion 18 by way of holders46. If carriage 31 moves out of its starting position away from abutment32, cam track block 36 moves, due to the interaction between thestationary pin 38 and the correspondingly configured cam track 37, inthe direction of the front flange 39 of carriage 31, with gripping arm14 simultaneously moving out of carriage 31 and coming into engagementwith the recess 13 of the disc holder 6 facing it. Shortly before pin 38leaves cam track 37, the rear face 47 of cam track block 36 comes to lieagainst an abutment rail 48 formed at upper portion 16 in order toprevent gripping arm 14 from sliding out of its moved-out position.Abutment rail 48 is connected with the lower portion by way of twoholders 49. In order to ensure an accurate alignment of the disc 5carried by carriage 31 into carrying arm 15 relative to the turntable 8of playback unit 7, a sensor 50 is attached to the frontal face of lowerportion 16 in order to determine the centered position of disc holder 6in carrying arm 15. Sensor 50 includes a two-armed lever 52 which ispivotally held in a bearing 51 and whose one arm 53 cooperates, by wayof a knob 55 formed at it in the center axis 54 of carrying arm 15 witha central knob 56 at the underside of disc holder 6 while its other arm58 which is charged by a tension spring 57, cooperates by way of anangled portion 59 at its end with a fork coupler 60 accommodated inlower portion 18. Next to fork coupler 60, there is another sensor 61configured as a fork coupler into which engages a web disposed behindplayback unit 7 so as to determine the end position of carrying arm 15above playback unit 7.

The belt drive 34 for moving carriage 31 includes a worm gear 62 and areversible motor 63. The worm wheel 64 of worm gear 62 is connected byway of a spring-tensioned friction coupling 65 with the drive wheel 66for the toothed belt 67 of belt drive 34. The endless toothed belt 67 isguided over a reversal roller 68 provided at lower portion 18 at anappropriate distance from drive wheel 66 and is fastened to carriage 31.The left carriage 31 in FIG. 9 is connected with the rear toothed belt67 while the right carriage 31 is coupled to the front toothed belt 67.If a disc holder 6 is taken out of a storage compartment 10 by means ofthe carriage 31 of the one extraction device 11, the carriage 31 of theother extraction device 11 serves as an abutment, if the disc holder isin its end position on the holding rails 17 of the carrying arm 15 oftransporting device 4 in which the disc 5 stored in disc holder 6 isconcentric with the turntable 8 of playback unit 7. Sensor 50 serves tomonitor this position of disc 5.

All motion sequences of disc player 1 are controlled and monitored by acentral control unit. If, for example, a disc 5 stored in the right discstorage magazine 3 has been selected by means of the keys on theoperator panel, transporting device 4 moves out of its starting positionabove playback unit 7 to a height which coincides with the height of thestorage compartment 10 of disc storage magazine 3 in which the discholder 6 holding the selected disc 5 is disposed. Then the extractiondevice 11 of transporting device 4 facing disc storage magazine 3 is putinto action so that initially, due to the action of cam track guide 35,the gripping arm 14 of carriage 31 engages in the recess 13 of discholder 6 facing it and then the movement of carriage 31 to its abutmenton the other carriage 31 causes disc holder 6 and disc 5 to betransported from storage compartment 10 to the holding rails 17 ofcarrying arm 15 of transporting device 4. As soon as disc holder 6 hasreached its final position on holding rails 17, which is being monitoredby sensor 50, transporting device 4 moves in the direction of playbackunit 7. While releasing disc 5 from disc holder 6, the central region ofdisc 5 is placed onto turntable 8. At the same time, in this endposition of transporting device 4, the magnetic attraction betweenmagnet 26 and the drive shaft 23 of turntable 8 causes the dischold-down insert 25 of disc hold-down member 22 to be pressed againstthe upper face of disc 5. If turntable 8 in playback unit 7 is caused torotate so that the information stored on disc 5 is read out optically byplayback head 9 to then be played back by way of appropriateloudspeakers. At the end of the information read-out from disc 5, thelatter is returned by transporting device 5 in an analogous manner toits associated storage compartment 10. Then transporting device 4 movesempty into its end position above playback unit 7 in which the cover 19of carrying arm 15 protects, in particular, playback head 9 of playbackunit 7 against soiling and improper access.

The above description of the drawings clarifies the details of thestructure and use of the disc player according to the invention.However, it is understood by the person skilled in the art that thebasic concept of the present invention can be put to much broader useand is not limited to the embodiment under specific consideration here.

I claim:
 1. A disc player, comprising:(A) a playback unit including aturntable having a driveshaft; (B) at least one disc storage magazinehaving a plurality of storage compartments arranged in a stack and aplurality of superposed disc holders stored therein, each disc holderaccommodating one disc; and (C) a transporting device movable in adirection of the stack for moving a desired disc and respective discholder back and forth between said storage compartment and said playbackunit and including:(1) a horizontally displaceable extraction device forextracting the respective disc holders from said magazine, comprising:asupport rod; a reciprocating carriage slidably guided on said supportrod, and having an upper portion and two facing flanges attached to theupper portion, each flange having an opening; a retractable gripping armmounted to said carriage and being extendable for engaging with a recessin the respective disc holders, said gripping arm being slidably guidedwithin the opening of one of said flanges; a cam track guide having acam track block connected with said gripping arm, and a pin fastened toan upper portion of said transporting device, said pin being engagablewith a cam track in said cam track block, said cam track guidemaintaining said gripping arm in a retracted position when said carriageis in a starting position and for moving said gripping arm into anextended position when said carriage is moved from said startingposition, said cam track block being slidably guided within the openingof the other one of said flanges; and a stationary abutment formaintaining said gripping arm in said extended position; (2) a dischold-down member for pressing the desired disc to be played onto saidturntable; and (3) a movable carrying arm for accommodating therespective disc holders, said movable carrying arm having an upper faceincluding a cover for gripping over a respective one of the disc holdersand disc therein, said cover having an opening essentially coaxial witha longitudinal axis of said drive shaft, said disc hold-down memberbeing insertable into said opening.
 2. A disc player according to claim1, wherein, said cover of said carrying arm, in a region of the disc,comprises a transparent pane.
 3. A disc player according to claim 1,wherein said drive shaft is magnetizable, the disc hold-down memberincludes a disc hold-down insert that is positioned with play in theopening of the cover and is provided in its center with a magnet which,in a rest position of the disc hold-down insert cooperates with amagnetizable steel plate that is inserted into a lid that closes theopening and, in an operating position of the disc hold-down insert,cooperates with the magnetizable drive shaft of the turntable of theplayback unit.
 4. A disc player according to claim 1, wherein thecarrying arm has an underside comprising two parallel holding rails forthe disc holder, said holding rails being positioned at a distance thatis greater than a width of the disc holder.
 5. A disc player accordingto claim 1, wherein the carrying arm has an associated sensor formonitoring the actual presence of a disc in the disc holder.
 6. A discplayer according to claim 1, wherein the carrying arm has an associatedsensing device for determining the size of a diameter of the disc in thedisc holder.
 7. A disc player according to claim 1, wherein the centerof the carrying arm has an associated sensor for monitoring a concentricposition of the disc stored in the disc holder relative to the turntableof the playback unit.
 8. A disc player according to claim 1, furthercomprising a sensor for determining an end position of the carrying armabove the playback unit, said sensor being positioned in a lower portionof the transporting device.
 9. A disc player according to claim 1,wherein, the pin initially engages the cam track when said carriage ismoved towards the starting position to thereafter retract the grippingarm to a position within the carriage.
 10. A disc player according toclaim 1, wherein one flange has an interior surface that abuts the camtrack block when the gripping arm is in the extended position.
 11. Adisc player according to claim 1, wherein the carriage is driveable by abelt drive including a worm gear, a drive wheel, a reversible motor, anda friction coupling provided between the worm gear and the drive wheel.12. A disc player according to claim 1, wherein said at least one discstorage magazine comprises two facing disc storage magazines, said discplayer further comprising a further carriage slidably guided to move onthe support rod and being driven by a belt drive equipped with wormgear, friction coupling and reversible motor, said further carriagehaving a further actuatable gripping arm connected with a further camtrack block that is equipped with a correspondingly extending cam trackassociated with a further pin that is correspondingly positioned at theupper portion of the transporting device.
 13. A disc player,comprising:(A) a playback unit including a turntable having adriveshaft; (B) at least one disc storage magazine having a plurality ofstorage compartments arranged in a stack and a plurality of superposeddisc holders stored therein, each disc holder accommodating one disc;and (C) a transporting device movable in a direction of the stack formoving a desired disc and respective disc holder back and forth betweensaid storage compartment and said playback unit, and including:(1) ahorizontally displaceable extraction device for extracting therespective disc holders from said magazine, comprising:a support rod; arail extending parallel to said support rod; a retractable gripping armbeing extendable for engaging with a recess in the respective discholders; a reciprocating carriage having said retractable gripping armmounted thereto, and being supported by said rail in a region of saidgripping arm; a cam track guide having a cam track block connected withsaid gripping arm, and a pin fastened to an upper portion of saidtransporting device, said pin being engagable with a cam track in saidcam track block, said cam track guide maintaining said gripping arm in aretracted position when said carriage is in a starting position and formoving said gripping arm into an extended position when said carriage ismoved from said starting position; and a stationary abutment formaintaining said gripping arm in said extended position; (2) a dischold-down member for pressing the desired disc to be played onto saidturntable; and (3) a movable carrying arm for accommodating therespective disc holders, said movable carrying arm having an upper faceincluding a cover for gripping over a respective one of the disc holdersand disc therein, said cover having an opening essentially coaxial witha longitudinal axis of said drive shaft, said disc hold-down memberbeing insertable into said opening.
 14. A disc player according to claim13, wherein said cover of said carrying arm comprises a transparent panein a region of the disc.
 15. A disc player, comprising:(A) a playbackunit including a turntable having a driveshaft; (B) at least one discstorage magazine having a plurality of storage compartments arranged ina stack and a plurality of superposed disc holders stored therein, eachdisc holder accommodating one disc; and (C) a transporting devicemovable in a direction of the stack for moving a desired disc andrespective disc holder back and forth between said storage compartmentand said playback unit, and including:(1) a horizontally displaceableextraction device for extracting the respective disc holders from saidmagazine, comprising:a reciprocating carriage; a retractable grippingarm mounted to said carriage and being extendable for engaging with arecess in the respective disc holder; a cam track guide having a camtrack block connected with said gripping arm, and a pin fastened to anupper portion of said transporting device, said pin being engagable witha cam track in said cam track block, said cam track guide maintainingsaid gripping arm in a retracted position when said carriage is in astarting position and for moving said gripping arm into an extendedposition when said carriage is moved from said starting position; alight barrier associated with said cam track block for detecting thestarting position of the carriage; and a stationary abutment formaintaining said gripping arm in said extended position; (2) a dischold-down member for pressing the desired disc to be played onto saidturntable; and (3) a movable carrying arm for accommodating therespective disc holders, said movable carrying arm having an upper faceincluding a cover for gripping over a respective one of the disc holdersand disc therein, said cover having an opening essentially coaxial witha longitudinal axis of said drive shaft, said disc hold-down memberbeing insertable into said opening.
 16. A disc player according to claim15, wherein said cover of said carrying arm comprises a transparent panein a region of the disc.